Australia's long-awaited naval shipbuilding plan acknowledges that South Australia will struggle to provide for the thousands of skilled workers needed for an expansion of the Navy's fleet. Foreign workers and interstate will be required to help meet these production deadlines.

The Naval Shipbuilding Plan outlines over $1 billion in infrastructure upgrades at the Osborne shipbuilding facilities and Western Australia's Henderson shipyards, while confirming construction is scheduled to begin on Australia's Future Frigates by 2020.

"This is the largest single Commonwealth investment in any single state … it is going to create another 5,000 jobs in shipbuilding directly again, almost all of which will be in South Australia, and another 10,000 in sustainment," Mr Turnbull told ABC Radio Adelaide this morning.

The document predicted by 2026 more than 5,200 workers would be needed in South Australia, but acknowledged foreigners would be "essential" to "fill middle management and supervisory roles".